Abstract:
A position sensor includes a stationary frame supporting a rotatable spool onto which a cable is wound in a plurality of individual windings. A distal end of the cable extends through a lead guide for attachment to an object whose position is desired to be sensed. As the object moves, the cable is would or unwound about the spool and the spool rotates in direct correlation to the movement of the object. The spool is retained in the frame through a threaded engagement between a threaded extension extending from the spool and a threaded opening in the frame. Thus, as the spool rotates, the spool travels along a linear path and a sensor determines the location of the threaded extension to determine the location of the object. A recoil spring is used which may be located within the spool itself.
Abstract:
A sensor mountable within a hydraulic cylinder provides a precision signal indicative of the position of the piston. The sensor includes a flexible connector attached between the cylinder piston and a converting element for sensing the piston displacement. The converting element comprises a pick-up spool, under tension, coupled to the other end of the connector and rotatable about an axis. A lead screw engages threads on the spool, and translates linearly when the spool rotates. A non-contacting electromechanical transducer senses the position of the lead screw, and provides an output signal proportional to the motion or position of the movable element. The transducer may be an LVDT or other transducer. A high-pressure seal assembly provides an electrical path between the sensor and an external connector. A piston stop prevents the piston from damaging the sensor. The sensor is held within the cylinder by port inserts threaded into standard cylinder hydraulic fluid ports and advanced inwardly to grip the sensor.
Abstract:
The present invention relates to an indicator for monitoring the position of a piston rod of a linear actuator utilized in robotic mechanisms. The indicator includes a precision toothed chain which is pulled by an extending piston rod and drawn in by a coil spring to maintain tension in the chain and a non-slipping relation with a sprocket wheel driven by the chain. A shaft encoder mounted on a shaft of the sprocket wheel delivers digitized quantities representative of the degree of rotation of the shaft and sprocket wheel and of the linear position of an actuating, linearly-movable end of the piston rod.
Abstract:
A method of installing a piston position sensor proximate to a closed end of a hydraulic cylinder is provided. The sensor is attached to the face of a piston and that piston/sensor combination is inserted into the cylinder tube to position the sensor in the desired location. When properly located within the cylinder tube, the sensor is affixed to the cylinder tube by means of beveled holes in the sensor that receive bolts threadedly inserted through the cylinder tube to further properly align the sensor within the cylinder tube. When so affixed, the sensor is then detached from the piston so that the piston can thereafter move independently of the sensor. A fixture is also used that allows the assembler to accurately align the angular orientation of the sensor prior to being inserted into the cylinder tube.
Abstract:
A fluid-powered actuator comprises a cylindrical body having a base proximate one extremity and a head proximate another extremity, a piston-rod assembly and a sensor module made of a removable cover and a position sensor. The piston-rod assembly is slidably mounted inside the cylindrical body. The base is provided with an opening adapted to accommodate the sensor therethrough. In operation, the cover seals the opening. The position sensor is mounted to an internal face of the cover so that the position sensor is operatively located inside the cylindrical body when the cover is in place. The position sensor is operative to measure a position of the piston-rod assembly. A sensor module adapted to sealably close the opening in the base comprises the position sensor mounted to an internal face of a cover structure. In operation, the position sensor is operatively located inside the actuator when the cover structure closes the opening.
Abstract:
A vehicle lift control maintains multiple points of a lift system within the same horizontal plane during vertical movement of the lift engagement structure by synchronizing the movement thereof. A vertical trajectory is compared to actual positions to generate a raise signal. A position synchronization circuit synchronizes the vertical actuation of the moveable lift components by determining a proportional-integral error signal.
Abstract:
A vehicle lift control maintains multiple points of a lift system within the same horizontal plane during vertical movement of the lift engagement structure by synchronizing the movement thereof. A vertical trajectory is compared to actual positions to generate a raise signal. A position synchronization circuit synchronizes the vertical actuation of the moveable lift components by determining a proportional-integral error signal.
Abstract:
A method of installing a piston position sensor proximate to a closed end of a hydraulic cylinder is provided. The sensor is attached to the face of a piston and that piston/sensor combination is inserted into the cylinder tube to position the sensor in the desired location. When properly located within the cylinder tube, the sensor is affixed to the cylinder tube by means of beveled holes in the sensor that receive bolts threadedly inserted through the cylinder tube to further properly align the sensor within the cylinder tube. When so affixed, the sensor is then detached from the piston so that the piston can thereafter move independently of the sensor. A fixture is also used that allows the assembler to accurately align the angular orientation of the sensor prior to being inserted into the cylinder tube.